Please DO NOT attempt this if your light is still within warranty, opening the light does void the warranty. Please open a support ticket or call us so we can assist you with a warranty repair.
Quite often lights will come in seeming to be dead when they are actually in a safety mode. This can happen from the battery being over-discharged and also when the light is charged using an unstable power source. By unplugging the battery from the board you effectively 'reboot' the circuit and bring the battery out of the safety mode.
If you remove the O-ring on accident or it has sand or salt on it then click here and watch the 'Closing Sola 2L' video for how to clean it and put it back properly.